κείμενο - "keímeno" - text

A lightweight and simple, native crystal library for text based interactive command line interfaces (TUI).

FZF like demo

Installation

Update your shard.yml to include keymeno

dependencies:
+  keimeno:
+    github: robacarp/keimeno

Usage

See the demos.

A basic command line utility can probably be built using the primitives provided herein: menu, prompt, text input. But that wouldn't be any fun if you were limited to those only.

To build your own interactive utility, subclass Keimeno::Base:

class CoolMenu < Keimeno::Base
  # The following methods provide high level anchoring into the TUI engine:

  # Display methods are called each time the interface needs to be updated
  def before_display
  end

  def display
  end

  # cleanup method is called (by default) on exit, via ctrl-c or otherwise
  def cleanup
  end

  # return_value is used to emit a result from the interface
  def return_value
  end

  # respond to specific keypresses with methods like these
  def key_ctrl_c
  end

  def key_alt_enter
  end

  # or respond to general keypresses with methods like these
  def key_pressed(keystroke)
  end

  def function_key(keystroke)
  end

  def character_key(keystroke)
  end

  # When you're done and it's time to cleanup and exit cleanly, call `finish!`
  def i_know_im_ready_to_exit
    finish!
  end
end

Responding to keypresses can happen at a few different altitudes depending on your needs. If you just want to respond to a special key or two (enter and ESC) and character keys, you might do this:

class CoolWidget < Keimeno::Base
  def key_enter
  end

  def key_esc
  end

  def character_key(keystroke)
  end
end

For close-to-readline bindings on your user inputs, the TextInput or Prompt modules can be included and will render a text input at the cursor location which responds reasonably close to what might be expected from a readline interface.

class MegaInputDevice < Keimeno::Base
  include Keimeno::TextInput

  def display
    print "What is your favorite color? "
  end

  def key_enter
    finish!
  end

  def return_value
    input_text
  end
end